If everything goes according to Shamees Aden's plan, you may one day never need to buy another pair of running shoes. The designer and biotech researcher unveiled herproduct concept, a collaboration with a University of Southern Denmark professor, at London's Wearable Futures conference. The shoes are 3D-printed using protocells -- molecules that are not alive but can be combined to create living organisms -- and conform to the wearer's foot like a second skin. After a run, they'd need basic care,like a houseplant, and they could also respond to pressure exerted by the wearer, inflating or deflating as needed to better cushion the foot. The technology needed to create a fully functioning prototype, however, is still about 20 years away.